US authorities have filed charges against a Chicago man, and are accusing him of stealing Bitcoin and Litecoin from his employer, which he later used for personal cryptocurrency trading.

The man is Joseph Kim, 24, of Chicago —who worked as an assistant trader for Consolidated Trading LLC, a Chicago trading firm. In September 2017, Consolidated extended its normal trading business with a cryptocurrency trading division, to which Kim was transferred soon after.

Kim sent $3,25 million to his own account

According to court documents obtained by Bleeping Computer, a week after Kim was assigned to this new department, he started moving Litecoin and later Bitcoin funds from the company's accounts to his own.

Managers noticed Kim's actions and confronted the accused several times. For example, when superiors noticed that Kim moved 980 Litecoin ($48,000) from the company's account, Kim told them he moved the funds to an offline Trezor wallet for security reasons.

Similarly, when bosses noticed Kim transferring Bitcoin out of company wallets, Kim claimed company Bitcoin funds were blocked and he was just in the middle of taking steps to unblock the money and recover the Bitcoin.

Nonetheless, despite numerous excuses, bosses noticed that after almost two months, cryptocurrency remained missing from company accounts.

The company lost over $600,000

According to a criminal complaint, the company found that during these months, Kim had siphoned $3,248,000 worth of Bitcoin and $48,000 worth of Litecoin from company accounts.

Kim did eventually return $1,236,000 worth of Bitcoin on his own, but a large amount remained missing.

That's when the company decided to confront Kim with their findings. Kim admitted to taking the funds in an email.

It was not my intention to steal for myself from [Consolidated] and until the end I was perversely trying to fix what I had already done. I can't believe I did not stop myself when I had the money to give back, and I will live with that for the rest of my life. You have every apology I have to give, I am sorry to betray you all like this.

The company did get back another $1,457,000 worth of Bitcoin from Kim after they sent representatives to his home, nonetheless, $603,000 worth of Bitcoin were unaccounted, and are presumed lost.

Evidence suggests that Kim traded for Bitcoin with personal funds and lost money. He's suspected of taking funds from the company in an attempt to cover personal losses, believing be could play Bitcoin's erratic price and recover some of his own funds, and then return the misappropriated money back to Consolidated Trading.

A warrant for his arrest was issued on February 15, and Kim turned himself in and appeared in court the next day. He faces fraud charges. The maximum sentence is 20 years in prison if found guilty.